Bicycles are hard to transport with passenger vehicles, especially cars. Bicycles do not fit in the trunks of most vehicles unless the bicycle is disassembled. Reassembling a bicycle can take significant time, however. A common solution is to put the bicycle on a bike rack that attaches to the vehicle. Bike racks usually rest on the roof or trunk of the vehicle. Some bike racks attach to a trailer hitch. Even bike racks have drawbacks, however. For example, bike racks that attach to the trunk or trailer hitch often limit access to the trunk or cargo space.